From 56eb1a1cf9fa7cb9b07ff4385d8d669b7e458457 Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Tue, 14 Dec 2021 13:56:00 +0800
Subject: [PATCH] Load fstab from system/etc

Caused by this commit: https://cs.android.com/android/_/android/platform/system/core/+/e98afa2687eb56184dad8569b929eba04fb93068

Fix #5057
---
 native/jni/init/twostage.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/native/jni/init/twostage.cpp b/native/jni/init/twostage.cpp
index 92b8c4719..bb878ef08 100644
--- a/native/jni/init/twostage.cpp
+++ b/native/jni/init/twostage.cpp
@@ -58,6 +58,7 @@ static void read_fstab_file(const char *fstab_file, vector<fstab_entry> &fstab)
 extern uint32_t patch_verity(void *buf, uint32_t size);
 
 void FirstStageInit::prepare() {
+    run_finally finally([]{ chdir("/"); });
     if (config->force_normal_boot) {
         xmkdirs(FSR "/system/bin", 0755);
         rename("/init" /* magiskinit */, FSR "/system/bin/init");
@@ -82,7 +83,7 @@ void FirstStageInit::prepare() {
     for (const char *suffix : {config->fstab_suffix, config->hardware, config->hardware_plat }) {
         if (suffix[0] == '\0')
             continue;
-        for (const char *prefix: { "odm/etc/fstab", "vendor/etc/fstab", "fstab" }) {
+        for (const char *prefix: { "odm/etc/fstab", "vendor/etc/fstab", "system/etc/fstab", "fstab" }) {
             sprintf(fstab_file, "%s.%s", prefix, suffix);
             if (access(fstab_file, F_OK) != 0) {
                 fstab_file[0] = '\0';
@@ -126,6 +127,10 @@ exit_loop:
         auto init = mmap_data("/init", true);
         init.patch({ make_pair("android,fstab", "xxx") });
     } else {
+        if (fstab_file[0] == '\0') {
+            LOGE("Cannot find fstab");
+            return;
+        }
         // Parse and load the fstab file
         read_fstab_file(fstab_file, fstab);
     }
@@ -192,8 +197,6 @@ exit_loop:
         }
     }
     chmod(fstab_file, 0644);
-
-    chdir("/");
 }
 
 #define INIT_PATH  "/system/bin/init"